This surveys the philosophies of music of the most important thinkers in Islam between the 9th and the 15th centuries A.D. It covers topics ranging from the physics and aesthetics of sound, the nature of music, its place in the total scheme of things and in human life, the relation between music, astronomy, astrology and meteorology, the relation between music and human feelings character and behaviour, to the question of whether a good Muslim should be allowed to listen to music at all, and if so, to which type. The book traces the influence of Greek, in particular Pythagorean and Aristoxenian, thinking in Islam on this subject, and aims to provide a philosophically coherent statement of thinking of the Islamic writers concerned, a clarification of their central arguments, as well as a critical evaluation of their line of thought. The author introduces a wide range of material from manuscript sources, including much that has not been published before.